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Troubleshooting startup or booting issues - Desktops

Startup and booting are synonymous terms referring to the time just after the computer has been powered on by using the power switch from a completely powered off condition. Resuming from suspend mfode is not included. Troubleshooting startup issues assumes the system has some indication of power, and the power-on self test (POST) may or may not complete successfully. The system does not completely boot to the operating system desktop or a DOS prompt.

Do not confuse video monitor (either CRT or flat panel) problems with computer problems. The monitor should always be verified as working properly before troubleshooting the computer.

Do not confuse a "dead" computer with a computer with startup problems. If the system does not have any indication of power, refer to Troubleshooting power issues.

Introduction to beep codes

Beep codes are an important and useful tool when troubleshooting booting issues. The count and sequence of beeps let the user know that the self-testing functions of the computer have found a hardware problem and indicate where to begin looking when attempting to fix the problem. If multiple beeps are heard during startup, refer to the appropriate Hardware Maintenance Manual to determine the cause as indicated by the beep code heard.

Beep codes vary by the number of beeps and the time interval between beeps. It may be necessary to restart the computer 2 or 3 times to determine the beep code. For example, to distinguish 1-3-1 beep code from a 2-1-2 beep code.

Solutions are usually listed in order from easiest to accomplish to harder to accomplish. However, a solution more likely to solve the problem may be listed before a solution that may be easier to accomplish.

No beeps are heard during startup

If the video monitor appears to be working correctly, but the system does not display any video after power on, no beeps are heard during boot, and there is no other indication of any power, refer to Troubleshooting power issues first.

Some systems are configured to start up quietly (no beep, and no memory count or checkpoint code display) when no errors are detected by POST. Therefore, the POST test may have completed successfully but some other failure may be present. To enable beeps and memory count when a successful POST occurs, do the following:

With the preceding changes made, a single beep should be heard to indicate the basic hardware is operating properly. If one beep is heard after making these changes, proceed to A single beep is heard during startup below.

Make sure the power supply 115/230 voltage selector switch is correctly set for your region. This switch is located on the rear of the system near the connection for the power cord. See the example below.

The exact location may vary from the example. Before changing the switch position, make sure to unplug the system first. Many replacement power supplies are shipped with this switch in the 230V position.

An incorrectly set voltage selector switch my result in a computer that continually reboots after the power switch is pressed. Test the system to see if the problem is corrected, and continue to the next step if the problem is not corrected.

Example of 115/230 voltage selector switch location

Attention: Applying 230 volts to a system set to 115 will ruin the power supply.

Perform a power supply reset. Unplug the power cord and hold the power button in for 10 seconds. Reattach the power cord and try to power on the system. Test the system to see if the problem is corrected, and continue to the next step if the problem is not corrected.

Some newer power supplies are equipped with LEDs to indicate power supply and system board diagnostic conditions. Refer to the table below, observing the state of the Power LED on the front of the computer and the 2 diagnostic LEDs on the power supply to determine the condition:

Power LED

Green
diagnostic LED

Yellow
diagnostic LED

Action

ON

ON

OFF

This is the normal condition of the LEDs when the power is OK.

OFF

OFF

OFF

Make sure the power cord is attached to a working electrical outlet.
If the electrical outlet is OK, replace the power supply.

OFF
(after the power button has been pressed)

ON

OFF

Replace the system board

ON

ON

ON

Replace the power supply

If the power supply LEDs indicate the normal condition, continue to the next step.

If any hardware has just been added, remove it. This includes internal devices such as memory or modems, and external devices such as printers or USB devices. If the system works after the devices are removed, the issue may be compatibility with the new hardware.

Some older operating systems, such as Windows NT, do not support plug and play installation of adapters and other devices. When installing additional devices in systems with non-plug and play operating systems, the devices must be manually configured. Frequently some settings, such as interrupt selection, must be made prior to the device being installed, either by making hardware changes on the device itself or by making changes to the operating system settings.

Continue to the next step if the problem is not corrected.

Disconnect and reconnect all remaining internal components.

Adapters, power connectors, cables, riser cards, and memory.

Some system boards are seated into risers. These should also be reseated.

Check for bent pins when cables are disconnected.

Connections frequently become loose when the computer is moved.

Test the system to see if the problem is corrected, and continue to the next step if the problem is not corrected.

If, after completing the steps above, the computer still does not beep, either the system board, power supply or processor appear to be defective. There is no definitive test to determine which component is at fault. The preferred order of replacement is power supply, system board, then processor.

Before replacing any FRUs, make sure that the latest level of BIOS is installed on the system. A down-level BIOS may cause false errors and unnecessary replacement of parts.

Important: If either the processor or the system board has been replaced, flash the BIOS before proceeding.

Attention: To prevent damage, the power cord must be unplugged from the system prior to working with any internal components.

Make sure the monitor is working. A symptom of "no video" does not always indicate the system is dead. No video means absolutely no video display output of any kind at any time during startup. Most monitors have some form of diagnostic self-test capability built into them. Refer to the monitor owners manual for directions. Test the system to see if the problem is corrected, and continue to the next step if the problem is not corrected.

Make sure the monitor is connected to the proper video connector. Some systems are equipped with 2 video connectors. Only 1 is enabled by default. Video output connectors are usually blue. Refer to the example below. Connector 1 is the video connector permanently connected to the system board. Connector 2 is the video adapter and, when installed, is the active video connection. Test the system to see if the problem is corrected, and continue to the next step if the problem is not corrected.

Test the system to see if the problem is corrected, and continue to the next step if the problem is not corrected.

Make sure the processor appears properly seated in its socket, and check to make sure the heat sink appears correctly fastened to the processor. Modern processors get very hot and must be cooled properly. Correct heat sink installation is required for proper cooling. Correct any improper installations found. Test the system to see if the problem is corrected, and continue to the next step if the problem is not corrected.

Refer to the Hardware Maintenance Manual for directions on how to remove and install a heat sink or processor.

Attention: Removing and replacing the heat sink and processor in most systems is an advanced procedure. It should be performed only by qualified personnel. Improper handling of the processor can result in damage to the processor and system board.

If, after completing the steps above, the computer still generates multiple beeps, either the system board, power supply or processor appear to be defective. There is no definitive test to determine which component is at fault. The preferred order of replacement is power supply, system board, then processor.

The system has indication of power, and completes POST, but does not boot to the operating system desktop or a DOS command prompt. Some video display is present or was present prior to the system stopping. The single beep indicates that the basic hardware, not necessarily all hardware needed to boot to an operating system, has passed POST. At this point, the problem can usually be described as something that is preventing the system from finding and loading the operating system. A problem with the operating system itself becomes much more likely rather than a hardware problem.

Note: Some of these checks may not apply to your system.

Attention: To prevent damage, the power cord must be unplugged from the system prior to working with any internal components.

Make sure the floppy diskette drive and CD-ROM drive do not have disks installed. This condition will can result in a "Non-system disk" error. Test the system to see if the problem is corrected, and continue to the next step if the problem is not corrected.

If a "Non-system disk" error displayed and no removable media disks are installed in the CD-ROM drive or diskette drive, the operating system is not being found on the hard disk drive. Go to Troubleshooting IDE hard disk drive issues.

If any installed bootable device, such as the hard disk drive, is not shown in the list of devices to select from, that device was not recognized by the BIOS during the POST. This condition must be corrected. Proceed to the appropriate troubleshooting document.

Disable any boot to network setting to make sure the Preboot eXecution Environment (PXE) is not trying to boot. PXE enables remote booting and system access before the computer can boot to a local operating system. If using an optional network adapter, refer to the owners manual for directions on how to change configuration settings. Test the system to see if the problem is corrected, and continue to the next step if the problem is not corrected.

Refer to the Hardware Maintenance Manual for directions on how to change the boot sequence.

Attempt to boot to safe mode. If using Microsoft Windows XP, restart the computer, and then press F8 during the startup to start the computer in Safe Mode with a command prompt. Type the following command at the command prompt, and then press ENTER:

%systemroot%\system32\restore\rstrui.exe

where %systemroot% is the directory where the Windows operating system is located. Follow the directions that appear to attempt to restore the computer to an earlier configuration. For more information on the use of System Restore, please refer to the Microsoft Knowledge Base at http://support.microsoft.com/.

If any hardware has just been added, remove it. This includes internal devices such as memory or network adapters, and external devices such as printers or USB devices. This includes replacement parts if the system has just been serviced.

Test the system to see if the problem is corrected, and continue to the next step if the problem is not corrected.

If the system works after the devices are removed, the issue may be compatibility with the new hardware. Try the devices on another identical system.

Some add on devices can be mistaken by the system to be startup devices. This can result in no startup or very slow startup conditions.

Attempt to boot to a bootable diskette or CD-ROM such as the Lenovo Enhanced Diagnostics. If the system boots to the diagnostic diskette, run the diagnostics routine on the entire system.

Swap the hard disk driveand cable with one known to work, if available.

If the system boots, the problem is with the removed hard drive, cable, the operating system installed on the hard drive or the connection may have been loose.

Note: Run Enhanced Diagnostics to test the hard disk drive prior to replacing the drive as defective.

Test the system to see if the problem is corrected, and continue to the next step if the problem is not corrected.

Reseat memory and adapter cards. Remove and reseat all power cables and data cables for the installed devices. Reseating is particularly important if the system was just moved. Test the system to see if the problem is corrected, and continue to the next step if the problem is not corrected.

Make sure the most recent BIOS code is installed. Test the system to see if the problem is corrected, and continue to the next step if the problem is not corrected.

Remove all nonstandard equipment and options from the system. Test the system to see if the problem is corrected, and continue to the next step if the problem is not corrected.

Make sure the processor fan, if installed, works.

Note: Some newer systems enable the fan to stop rotating during normal operation. The fan only turns on if the system gets hot.

If, after completing the steps above, the computer still stops after generating one beep use the "Submit a request" link in the "Need more help?" section to contact the Lenovo Support Center technician for further instructions.